Outboard motor with dual cooling system

ABSTRACT

An outboard motor including a propulsion unit connected to a boat attachment element for providing vertical and horizontal swinging movement of the propulsion unit relative to the boat, which propulsion unit includes a rotary internal combustion engine including a first housing assembly comprising wall surfaces defining aligned first and second trochoid shaped rotor cavities and additional wall surfaces defining a first water jacket system adjacent to the first and second rotor cavities and having inlet and outlet ports, together with a second housing assembly comprising wall surfaces defining aligned third and fourth trochoid shaped rotor cavities and additional wall surfaces defining a second water jacket system adjacent to the third and fourth rotor cavities and having inlet and outlet ports, bolts securing together the first and second housing assemblies, a lower unit rigidly supporting the engine and including a propeller rotatably supported by the lower unit and operably connected to the engine, a water pump driven by the engine and having an inlet communicating with the water, and a water conduit communicating between the pump and separately with each of the first and second water jacket system inlet ports.

United States Patent 1 Miller et al.

[73] Assignee: Outboard Marine Corporation,

Waukegan, Ill.

[22] Filed: Feb. 20, 1974 [21] Appl. No.: 444,049

[52] US. CL. 115/17 [51] Int. Cl.'- B6311 5/13 [58] Field of Search 115/12 A. l7. 18 R. 34 R 115/35; 123/801. 8707. 41.01, 41.28:

[56] References Cited UNITED STATES PATENTS 1,786.835 12/1930 Evinrude .4 115/17 33177367 2/1963 Froede... 418/210 3,286.7(10 11/1966 Froede 123/8111 3.43L882 3/1969 lrgens t. 115/17 3520.270 7/1970 Miller 115/17 3.552.121 l/l97l Kitagawa et a1, 115/17 Primary Exumizmr-Trygve M. Blix Assistant E.\'aminm'lesus D. Sotclo Attorney, Agent or Firm-Michael, Best & Friedrich 1 1 Sept. 30, 1975 [57 1 ABSTRACT An outboard motor including a propulsion unit connected to a boat attachment element for providing vertical and horizontal swinging movement of the propulsion unit relative to the boat, which propulsion unit includes a rotary internal combustion engine including a first housing assembly comprising wall surfaces defining aligned first and second troehoid shaped rotor cavities and additional wall surfaces defining a first water jacket system adjacent to the first and second rotor cavities and having inlet and outlet ports, together with a second housing assembly comprising wall surfaces defining aligned third and fourth trochoid shaped rotor cavities and additional wall surfaces defining a second water jacket system adjacent to the third and fourth rotor cavities and having inlet and outlet ports bolts securing together the first and second housing assemblies a lower unit rigidly supporting the engine and including a propeller rotatably supported by the lower unit and operably connected to the engine. a water pump driven by the engine and having an inlet communicating with the water and a water conduit communicating between the pump and separately with each of the first and second water jacket system inlet ports.

5 Claims. 3 Drawing Figures US. Patent Sept. 30,1975 Sheet 10f2 3,908,579

U.S. Patant Sept. 30,1975 Sheet 2 of2 3,908,579

OUTBOARD MOTOR WITH DUAL COOLING SYSTEM BACKGROUND OF THE INVENTION The invention relates generally to outboard motors and, more particularly, to outboard motor engine cooling systems. Still more particularly, the invention re lates to cooling systems for outboard motors having a plurality of aligned combustion chambers.

SUMMARY OF THE INVENTION The invention provides an outboard motor comprising a propulsion unit connected to a boat attachment means for vertical and horizontal swinging movement of the propulsion unit relative to the attachment, which propulsion unit includes an internal combustion engine including first and second combustion chambers arranged in alignment with each other, and first and second water jackets respectively associated with the first and second combustion chambers and respectively in cluding inlet ports and outlet ports, together with a lower unit rigidly supporting the engine and including a gear box normally partially submerged in water, a propeller rotatably supported by the gear box and operably connected to the engine, a water pump driven by the engine and having an inlet communicating with the water, and a water conduit communicating between the pump and separately with each of the first and second water jacket inlet ports.

In further accordance with the invention, the engine comprises a rotary internal combustion engine and the combustion chambers comprise aligned trochoid shaped cavities.

The invention also provides an outboard motor comprising a propulsion unit, connected to a boat attachment means for vertical and horizontal swinging movement of the propulsion unit relative to the attachment means, which propulsion unit includes a rotary internal combustion engine including a first housing assembly comprising means defining aligned first and second trochoid shaped rotor cavities and means defining a first water jacket system adjacent to the first and second rotor cavities and having inlet and outlet ports, a second housing assembly comprising means defining aligned third and fourth trochoid shaped rotor cavities and means defining a second water jacket system adjacent to the third and fourth rotor cavities and having inlet and outlet ports, and means securing together the first and second housing assemblies, together with a lower unit rigidly supporting the engine and including a gear box normally partially submerged in water, a propeller rotatably supported by the gear box and operably connected to the engine, a water pump driven by the engine and having an inlet communicating with the water, and a water conduit communicating between the pump and separately with each of the first and second water jacket system inlet ports.

In further accordance with the invention, the first and second rotor cavities are aligned with the third and fourth rotor cavities, and the first housing assembly comprises first and second housing members respectively including first wall means at least partially defining the first and second rotor cavities and second wall means at least partially defining first and second water jackets forming a part of the first water jacket system with the first Water jacket including the first water jacket system inlet port and with the second water jacket including the first water jacket system outlet port, together with an intermediate member located between the first and second housing members and including wall means further defining the first and second rotor cavities and additional wall means defining a third water jacket communicating between the first and second water jackets and forming a part of the first water jacket system. Still further, the second housing assembly comprises third and fourth housing members respectively including first wall means at least partially defining the third and fourth rotor cavities and second wall means at least partially defining fourth and fifth water jackets forming a part of the second water jacket system with the fourth water jacket including the second water jacket system inlet port and the fifth water jacket including the second water jacket system outlet port, together with an intermediate member located between the third and fourth housing members and including wall means further defining the third and fourth rotor cavities and additional wall means defining a sixth water jacket communicating between the fourth and fifth water jackets and forming a part of "the second water jacket system. i

One of the principal features of the invention is the provision of an outboard motor including anin-line multi-combustion chamber engine having two parallel water jacket systems with each system being associated with at least one combustion chamber.

Another of the principal features of the invention is the provision of an outboard motor which includes a rotary internal combustion engine comprising two housing assemblies located in vertically aligned relation to each other, and each including a separate water jacket system supplied with cooling water from a common pump located in the outboard motor lower unit.

Another of the principal features of the invention is the provision of an outboard motor as referred to in the preceding paragraph and in which each housing assembly includes two rotating combustion chambers.

Still another of the principal features of the invention is the provision of an outboard motor having an engine with aligned multiple combustion chambers and a cooling arrangement adapted to optimize uniform cooling of the combustion chambers.

Other features and advantages of the invention will become known by reference to the following drawings, general description, and claims.

THE DMWINGS FIG. 1 is a side elevational view, partially broken away, partially in section, and partially schematic of a marine propulsion device in the form of an outboard motor including a multi-rotor rotary internal combustion engine.

FIG. 2 is a view taken generally along line 2-2 of FIG. 1, with parts broken away and in section.

FIG. 3 is a view taken generally along line 33 of FIG. 1, with parts broken away.

Before explaining the invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of parts set forth in the following general description or illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

GENERAL DESCRIPTION Shown in the drawings is an outboard motor 11 which includes a propulsion unit 13 adapted to be connected to the stern of a boat by attachment means 15 affording horizontal swinging or steering rhovement of the propulsion unit 13 relative to the boat and affording vertical swinging movement of the propulsion unit 13 relative to the boat. Any suitable construction can be employed for such attachment means 15.

The propulsion unit 13 comprises a lower unit including a gear box 19 which can include a reversing transmission 21 and which rotatably supports a propeller 23. Rigidly carried on the top of the lower unit 17 below the at-rest water line 25 is a bucket or water guard 27. Rigidly carried on the top of the lower unit 17 within the bucket or water guard 27 is an internal combustion engine 29 having a plurality of vertically in-line combustion chambers.

Various reciprocating and rotary piston internal combustion engine constructions can be employed. In the illustrated construction, the engine 29 is a'rotary internal combustion engine assembled from a vertically extending series of horizontally extending members, each of which includes one or more flat surfaces for mating with an adjacent flat surface of an adjacently located member.

More specifically, the rotary internal combustion engine 29 comprises lower and upper housing assemblies 31 and 33, each including two rotor cavities. Still more particularly, the lower housing assembly 31 comprises first and second housing members 35 and 37, respectively including first wall means partially defining first and second trochoid shaped rotor cavities 39 and 41, and second wall means at least partially defining first and second water jackets 43 and 45 extending circumferentially of the rotor cavities 39 and 41.

Located between the first and second housing members 35 and 37 is an intermediate member 47 including means further defining the first and second rotor cavities 35 and 37 and the first and second water jackets 43 and 45 and additional means defining a third water jacket 49 arcuately extending intermediate the first and second rotor cavities 39 and 41 and providing a coolant passage connecting the first and second water jackets 43 and 45. Located below the first housing member 35 is a lower end wall member 51 which further defines the first rotor cavity 39 and the first water jacket 43, and which includes (See FIG. 2) an inlet port 53 communicating with the first water jacket 43. Located above the second housing member 37is an upper end wall member 55 which further defines the second rotor cavity 41 and the second water jacket 45 and which includes (See FIG 3) an outlet port 57 for the second water jacket 45. The first and second housing members 35 and 37, the intermediate member 47, and the lower and upper end wall members 51 and 55 are assembled in parallel relation to one another with the trochoid shaped rotor cavities 39 and 41 in aligned relation by any suitable means, such as the bolts 59.

The upper housing assembly 33 includes third and fourth housing members 61 and 63 respectively including first wall means partially defining third and fourth trochoid shaped rotor cavities 65 and 67 and second wall means at least partially defining fourth and fifth water jackets 69 and 71 extending circumferentially of the third and fourth cavities 65 and 67. Located between the third and fourth housing members 61 and 63 is a second intermediate member 73 including wall means further defining the third and fourth cavities 65 and 67 and the fourth and fifth water jackets 69 and 71 and additional means defining a sixth water jacket 75 extending arcuately intermediate the third and fourth rotor cavities 65 and 67 and providing a coolant passage between the fourth and fifth water jackets 69 and 71. Located below the third housing member 61 is a lower end wall member 77 which further defines the third rotor cavity 65 and the fourth water jacket 69 and which includes an inlet port 79 communicating with the fourth water jacket 69. Located above the fourth housing member 63 is an upper end wall member 81 which further defines the fourth rotor cavity 67 and the fifth water jacket 71 and which includes an outlet port 83 for the fifth cooling jacket 71. The upper and lower housing member 61 and 63, the intermediate member 73, and the lower and upper end wall members 77 and 81 are assembled in parallel relation to each other with the third and fourth trochoid shaped rotor cavities 65 and 67 in aligned relation by any suitable means, such as the bolts 85.

Thus, it will be seen that the first, second, and third water jackets 43, 45 and 49 constitute a first water jacket system having an inlet port 53 and an outlet port 57, and the fourth, fifth and sixth water jackets 69, 71 and 75 constitute a second water jacket system having an inlet port 79 and an outlet port 83.

Extending vertically through the lower and upper housing assemblies 31 and 33 is a crankshaft 91 which includes a lower crankshaft portion 93 which is rotatably supported by the lower housing assembly 31 and which extends through the first and second rotor cavities 39 and 41, and an upper crankshaft portion 95 which is physically separate from the lower crankshaft portion 93, which is rotatably supported by the upper housing assembly'33, and which extends through the third and fourth rotor cavities 65 and 67.

Still more specifically, the lower crankshaft portion 93 includes first and second eccentric portions 97 and 99 respectively rotatably supporting first and second rotors 101 and 103 in the first and second rotor cavities 39 and 41, and the upper crankshaft portion 95 includes third and fourth eccentric portions 105 and 107 respectively rotatably supporting third and fourth rotors 109 and 1 1 1 extending in the third and fourth rotor cavities 65 and 67. Each of the rotors v101, 103, 109 and 111 is generally triangular in shape and, in response to respective rotation in the first, second, third and fourth rotor cavities 39, 41, 65 and 67, generates first, second, third and fourth rotatable chambers in which combustion takes place.

Provided on each of the rotors 101, 103, 105 and 107 and on the associated housing assemblies 31 and 33 is gear means 115 for effecting relative rotation between the rotors 101, 103, 109 and 111 and the housing assemblies 31 and 33 and between the rotors 101, 103, 109 and 11 1 and the crankshaft 91 in response to combustion in the rotating chambers.

In order to operatively unify the upper and lower crankshaft portions 93 and 95,, suitable coupling means 117 are provided therebetween to maintain the crankshaft portions 93 and 95 in proper angular relationship and to transmit torque.

Means are also provided for securing together the lower and upper housing assemblies 31 and 33 with all of the trochoid shaped rotor cavities 39, 41, 65 and 67 in alignment with one another. In the illustrated construction, such securing means is provided by through bolts 1 19 extending through the lower and upper housing assemblies 31 and 33. As also can be seen from the drawings, the upper end wall member 55 of the lower housing assembly 31 extends forwardly above the guard or bucket 27 and is connected to a kingpin 121 which forrns'a part of the beforementioned attachment means and which also extends into the lower unit 19 The upper crankshaft portion 95 extends above the upper end wall member 81 and is connected to a flywheel 125 which carries various components of a suitable ignition system.

Inorder to supply cooling water to the cooling jackets, the lower unit 17 further includes a water pump 131 which is driven by the engine 29 and which includes an inlet l33'normally located underwater. While other arrangements-could be employed, in the illustrated construction, theinlet 133 is located at the front end of the gear box 19 and communicates with the pump 131 through a duct 135 and through a passage 137 in the lower unit 17.

vln order to separately supply water to each of the cooling jacket systems, there is provided conduit means which communicates with the pump .131 and separately with each of the first and fourth water jackets 43 and 69. More particularly, such conduit means includes a pump discharge pipe or line 139 which communicates with the pump 131, which extends through the bucket 27, and which includes afirst branch pipe 141 communicating with the first water jacket inlet port 53 in the lower end Wall member 51 of the lower housing assembly 31, together with a second branch pipe 143 which communicates with the fourth cooling jacket inlet port 79 located in the lower end wall member 77 of the upper housing assembly 33.

Conduit means are also provided for discharging cooling water from the second and fifth water jackets 45 and 71. More specifically, the second water jacket outlet port 57 in the upper end wall 55 of the lower housing assembly 31 communicates with a discharge duct 15] which drains into a water jacket 153 extending around an exhaust gas discharge pipe 155 communicating with the rotor cavities 39, 41, 65 and 67. In addition, the fifth water jacket outlet port 83 in the upper end wall member 81 of the upper housing assembly 33 communicates with a discharge duct 161 which also drains into the water jacket 153 extending around the :exhaust gas discharge pipe 155.

At its lower end, the exhaust gas discharge pipe 155 is supported from the lower unit 17 for communication discharging cooling water from the second and fifth Water jackets 45 and 71.

In operation, one portion of the flow of cooling water discharged from the pump 131 flows through the first branch pipe 141 to the first water jacket 43 and then flows, in series: through the third water jacket 49 and through the second 'water' jacket 45 and through the dischargeduct 151 for overboard discharge. Another portion of the cooling water discharged from the pump 131 flows through the second branch pipe 143 to the fourth water jacket 69 and then flows, in series, through the sixth water jacket 75, and through the fifth water jacket 71, and through the discharge duct 161* for overboard dischargein common with 'the'dis'c'harge' from the discharge duct 151.1-lowever, if desired,- separate overboard discharges for the second and fifth water jackets 45 and 71 can be employed. i

As a consequence of the foregoing,the in-Iine'engine block includes two parallel water j'acketsys tems' each cooling one or more combustion chainbe'rsso as to reduce variation in heat withdrawn froriithe various combustion chambers and therebyfto provide for more uni form engine temperature and operation. A

Various of the'features ofthe invention are set forth in the following claims.

We claim: I g I 1. An outboard motor comprising means adapted for attachment to the ster'n of a boat and a propulsion unit connected to saidattachment means for vertical and horizontal swinging movement relative tosaid attachment means, said propulsion unit includingja rotary internal combustion engine including a first housing assembly comprising means defining aligned first second trochoid shaped rotor. cavities and mean'sdefiriing a first water jacket system adjacent to said first and sec ond rotor cavities andhaving: inlet and outlet ports, said first housing assembly further comprising first and second housing members respectively including first wall means at least partially defining said first and second rotor cavities and second wall means at least partially defining first and second Water jackets forming a part of said first water jacket system, said first water jacket including said first water jacket system inlet port and said second water jacket including said first water jacket system outlet port, said first housing assembly further comprising an intermediate member located between said first and second housing members and including wall means further defining said first and second rotor cavities and additional wall means defining a third water jacket communicating between said first and second water jackets and forming a part of said first water jacket system, a second housing assembly comprises means defining aligned third and fourth trochoid shaped rotor cavities and means defining a second water jacket system adjacent to said third and fourth rotor cavities and having inlet and outlet ports, said second housing assembly comprising third and fourth housing members respectively including first wall means at least partially defining said third and fourth rotor cavities and second wall means at least' partially defining fourth and fifthwater jackets forming a part of said second water jacket system, said fourth water jacket including said second water jacket system inlet port and said fifth water jacket including said second water jacket system outlet port, said second housing assembly further comprising an intermediate member located between said third and fourth housing members and including wall means further defining said third and fourth rotor cavities and additional wall means defining a sixth water jacket communicating between said fourth and fifth water jackets and forming a part of said second water jacket system, and means securing together said first and second housing assemblies, a lower unit rigidly supporting said engine and including a gear box normally partially submerged in water, a propeller rotatably supported by said gear box and operably connected to said engine, a water pump driven by said engine and having an inlet communicating with the water, and a water conduit communicating between said pump and separately with 'each of said first and second water jacket system inlet ports.

,2. An outboard motor in accordance with claim 1 and further including means connected to each of said outlet ports for overboard discharge of water.

,3. An outboard motor in accordance with claim 2 andfurther including an exhaust pipe communicating with said combustion chambers and wherein said overboard water discharge means includes a water jacket located around said exhaust pipe and communicating with an underwater discharge outlet.

4. An outboard motor in accordance with claim 1 wherein said first and second rotor cavities are aligned with said third and fourth cavities.

5. An outboard motor comprising means adapted for attachment to the stern of a boat and a propulsion unit connected to said attachment means for vertical and horizontal swinging movement relative to said attachrrre'nt means, said propulsion unit including a rotary internal combustion engine including a first housing assembly comprising means defining aligned first and secondti'ochoid shaped rotor cavities and means defining a first water jacket system adjacent to said first and second rotor cavities and having inlet and outlet ports, said first housing assembly further comprising first and second housing members respectively including first wall means at least partially defining said first and second rotor cavities and second wall means at least partially defining first and second water jackets forming a part of said first water jacket system, said first water jacket including said first water jacket system inlet port and said second water jacket including said first water jacket system outlet port, a second housing assembly comprising means defining aligned third and fourth trochoid shaped rotor cavities and means defining a second water jacket system adjacent to said third and fourth rotor cavities and having inlet and outlet ports, said second housing assembly comprising third and fourth housing members respectively including first wall means at least partially defining said third and fourth rotor cavities and second wall means at least partially defining third and fourth water jackets forming a part of said second water jacket system, said third water jacket including said second water jacket system inlet port and said fourth water jacket including said second water jacket system outlet port, and means securing together said first and second housing assemblies, a lower unit rigidly supporting said engine and including a gear box normally partially submerged in water, a propeller rotatably supported by said gear box and operably connected to said engine, a water pump driven by said engine and having an inlet communicating with the water, and a water conduit communicating between said pump and separately with each of said first and second water jacket system inlet ports. 

1. An outboard motor comprising means adapted for attachment to the stern of a boat and a propulsion unit connected to said attachment means for vertical and horizontal swinging movement relative to said attachment means, said propulsion unit including a rotary internal combustion engine including a first housing assembly comprising mEans defining aligned first and second trochoid shaped rotor cavities and means defining a first water jacket system adjacent to said first and second rotor cavities and having inlet and outlet ports, said first housing assembly further comprising first and second housing members respectively including first wall means at least partially defining said first and second rotor cavities and second wall means at least partially defining first and second water jackets forming a part of said first water jacket system, said first water jacket including said first water jacket system inlet port and said second water jacket including said first water jacket system outlet port, said first housing assembly further comprising an intermediate member located between said first and second housing members and including wall means further defining said first and second rotor cavities and additional wall means defining a third water jacket communicating between said first and second water jackets and forming a part of said first water jacket system, a second housing assembly comprises means defining aligned third and fourth trochoid shaped rotor cavities and means defining a second water jacket system adjacent to said third and fourth rotor cavities and having inlet and outlet ports, said second housing assembly comprising third and fourth housing members respectively including first wall means at least partially defining said third and fourth rotor cavities and second wall means at least partially defining fourth and fifth water jackets forming a part of said second water jacket system, said fourth water jacket including said second water jacket system inlet port and said fifth water jacket including said second water jacket system outlet port, said second housing assembly further comprising an intermediate member located between said third and fourth housing members and including wall means further defining said third and fourth rotor cavities and additional wall means defining a sixth water jacket communicating between said fourth and fifth water jackets and forming a part of said second water jacket system, and means securing together said first and second housing assemblies, a lower unit rigidly supporting said engine and including a gear box normally partially submerged in water, a propeller rotatably supported by said gear box and operably connected to said engine, a water pump driven by said engine and having an inlet communicating with the water, and a water conduit communicating between said pump and separately with each of said first and second water jacket system inlet ports.
 2. An outboard motor in accordance with claim 1 and further including means connected to each of said outlet ports for overboard discharge of water.
 3. An outboard motor in accordance with claim 2 and further including an exhaust pipe communicating with said combustion chambers and wherein said overboard water discharge means includes a water jacket located around said exhaust pipe and communicating with an underwater discharge outlet.
 4. An outboard motor in accordance with claim 1 wherein said first and second rotor cavities are aligned with said third and fourth cavities.
 5. An outboard motor comprising means adapted for attachment to the stern of a boat and a propulsion unit connected to said attachment means for vertical and horizontal swinging movement relative to said attachment means, said propulsion unit including a rotary internal combustion engine including a first housing assembly comprising means defining aligned first and second trochoid shaped rotor cavities and means defining a first water jacket system adjacent to said first and second rotor cavities and having inlet and outlet ports, said first housing assembly further comprising first and second housing members respectively including first wall means at least partially defining said first and second rotor cavities and second wall means at least partially defining first and second water jackets forming a part of said first water jAcket system, said first water jacket including said first water jacket system inlet port and said second water jacket including said first water jacket system outlet port, a second housing assembly comprising means defining aligned third and fourth trochoid shaped rotor cavities and means defining a second water jacket system adjacent to said third and fourth rotor cavities and having inlet and outlet ports, said second housing assembly comprising third and fourth housing members respectively including first wall means at least partially defining said third and fourth rotor cavities and second wall means at least partially defining third and fourth water jackets forming a part of said second water jacket system, said third water jacket including said second water jacket system inlet port and said fourth water jacket including said second water jacket system outlet port, and means securing together said first and second housing assemblies, a lower unit rigidly supporting said engine and including a gear box normally partially submerged in water, a propeller rotatably supported by said gear box and operably connected to said engine, a water pump driven by said engine and having an inlet communicating with the water, and a water conduit communicating between said pump and separately with each of said first and second water jacket system inlet ports. 